Horizontal drilling of well bores is a relatively recent technology where an initial segment of a well bore extends in a generally vertical direction and then is angled in a direction which can be normal to a vertical or with other angular relationships with respect to the initial vertical segment of the well bore. Where a horizontal or non-vertical section of the well bore traverses earth formations which contain hydrocarbons it is desirable to isolate selected formations from one another along a segment of the well bore from other sections along the well bore.
The present invention provides a practical system for obtaining a cement type sealing mechanism in the annulus between a well pipe and a well bore in horizontal or non-vertical sections of a well bore.
In U.S. Pat. No. 5,082,062 a system is disclosed where an inflatable packer in a string of pipe has a latching profile. An actuating tool carried on a string of tubing is receivable in the inflatable packer and is mechanically arranged to have latching fingers for selectively engaging the latching profile so that downward motion on the string of tubing can be used to set the inflation tool in the inflatable packer and permit use of cement or mud slurry to inflate the inflatable packer. This system has a certain mechanical complexity and requires the latching profile to be located below the inflatable packer and uses weight set packing elements.
Where multiple inflatable packers with different lengths are utilized, the location of a latching profile above the packer permits a single tool to be uniformly applicable in actuating the packers because the profile and actuating valve can be uniformly spaced irrespective of the length of the packer. Also the tool is considerable shorter which is always an advantage.